Substrate-controlled And Highly Stereoselective Synthesis Of2-aminobut-2-ene-1,4-diones

Highly stereoselective synthesis of compounds is one of the most important parts in the methodology of organic synthetic chemistry. The compounds which have special spatial configuration are useful both in nature products and in pharmaceuticals and are important intermediates in organic synthesis. Taking into account of the important value of these compounds, it is much more important to stereoselectively synthesis them. Therefore, the development of new strategys for stereochemistry has been the driving force for numerous synthetic efforts. Meanwhile, with the crucial function of "substrate-controlled" strategy in the spatial configuration, chemists are increasingly concerned about the use of "substrate controlled" strategy to stereoselective synthesis of target compounds.On the basis of this concept, in this dissertation, we have investigated substrate-controlled and highly stereoselective synthesis of2-aminobut-2-ene-1,4-diones, and disclosed the possible mechanism. The main content is as follows:In chapter1, we highlighted the influencing factors of stereochemistry, the synthetic methods and applications of2-aminobut-2-ene-1,4-diones. Subsequently, we put forward our research topic based on "substrate controlled" strategy and our previous research on2-methylthio-substituted1,4-enediones.In chapter2, Inspired by the cognition of the importance of2-aminobut-2-ene-1,4-diones, we continue our study on the base of our preliminary work of2-methylthio-substituted1,4-enediones. An unprecedented reaction between2-methylthio-substituted1,4-enediones and primary/secondary amines has been disclosed to afford corresponding Z/E2-amino-2-ene-1,4-dione. More importantly, based on the controlled experiment, the reaction mechanism was supposed to be addition-elimination or substitution-isomerization. All the compounds of2-aminobut-2-ene-1,4-diones are characterized by1H NMR,13C NMR, IR and MS. In additional, eight compounds are further confirmed by X-ray single crystal diffraction. The X-ray single crystal data demonstrate that the primary amines with2-methylthio-substituted1,4-enediones converted into the corresponding Z isomers; the secondary amines with2-methylthio-substituted1,4-enediones converted into the corresponding E isomers.1H NMR spectrum of compounds showed the existence of Hydrogen bonded N-H in Z-isomer.